For some years, different types of radio networks for wireless communication have been developed to provide radio access for various wireless devices. The radio networks are constantly improved to provide better coverage and capacity to meet the demands from subscribers using increasingly advanced services and devices such as smartphones and tablets, which may require considerable amounts of bandwidth and resources for data transport in the networks. A limiting factor for capacity of a radio network is the amount of available radio resources, e.g. in terms of time, frequency bandwidth and transmit power. The capacity of a radio network can be improved by utilizing any available radio resources as efficiently as possible, e.g. by reducing or minimizing the amount of signaling between the devices and the network in order to use the radio resources for communication of payload data and any mandatory messages.
In this disclosure, the term “wireless device” is used to represent any communication entity capable of radio communication with a radio network by sending and receiving radio signals, such as e.g. mobile telephones, tablets, laptop computers and so-called Machine-to-Machine, M2M, devices. Another common generic term in this field is “User Equipment, UE” which could also be used instead of wireless device. Further, the term “network node”, is used herein to represent any node of a radio network that is operative to communicate radio signals with wireless devices, or to control some network entity having radio equipment for receiving/transmitting the radio signals. The network node in this disclosure could also be referred to as a base station, radio node, e-NodeB, eNB, NB, base transceiver station, access point, etc., depending on the type of network and terminology used.
When a wireless device is connected to a network node of a radio network, the network node needs information about capabilities of the wireless device, so as to be able to configure and schedule the wireless device in a suitable manner such that the device will operate properly and efficiently. For example, certain features, functions and parameter settings are only possible to use in a radio communication if the wireless device is capable of handling and using those features, functions and parameter settings. It is therefore required that the wireless device provides its capabilities to the network node before a radio communication can be executed. Procedures have been defined for providing such device capabilities to the network.
FIG. 1 illustrates a simple example of how this is basically done when a wireless device 100 communicates with a network node 102 of a radio network over a radio interface and performs an attachment procedure. A node called Mobility Management Entity, MME, 104 is also shown in this example which is a node defined for Long Term Evolution, LTE, networks. The MME node 104 typically maintains various information about wireless devices present in the network such as temporary identities and device capabilities, among other things.
A first action 1:1 illustrates a procedure for establishing a connection between the wireless device 100 and the network node 102, often referred to as network attachment, which typically involves several messages communicated back and forth, as schematically illustrated by multiple two-way arrows. These messages depend on the type of network and protocols used, and may e.g. relate to synchronization, random access, Radio Resource Control (RRC), regulation of transmit power and other radio parameters, and so forth. The MME node 104 is typically involved for transfer of RRC information in this establishment procedure, as schematically illustrated by some further dashed two-way arrows.
Once the radio connection has been established, the network node 102 sends a capability enquiry to the wireless device 100, in a further action 1:2, in order to acquire knowledge about what functions, features and parameters the device 100 is capable of using in the forthcoming radio communication. In response thereto, the wireless device 100 sends its device capabilities to the network node 102 in a further action 1:3. The network node 102 may then accordingly forward a so-called capability information indication, to the MME node 104 in a further action 1:4.
The network node 102 may also acquire the device capabilities of the wireless device 100 after handover completion, i.e. when the device 100 has been handed over from a source network node to the target network node 102, or at state transition from idle to connected state. In either case, at least actions 1:2 and 1:3 may be performed here as well. Alternatively, if the capabilities of the wireless device 100 have been stored previously in the MME node 104, the network node 102 may be able to retrieve them therefrom. A next action 1:5 illustrates that the network node 102 configures and/or schedules the wireless device 100 for radio communication in accordance with the received device capabilities, and the radio communication is conducted in an action 1:6.
Some examples of device capabilities that are typically provided to the network, e.g. as shown in FIG. 1, include various parameters for radio access e.g. related to different protocols, Radio Frequency (RF), signal measurements, and so forth. The device capabilities may also include information about a range of supported features which may be optional or conditionally mandatory. For such a feature, the capability information also indicates whether the feature has been implemented and successfully tested. For LTE networks, the device capabilities are described in more detail in the 3GPP specification TS 36.306, version 12.6.0.
It is a common practice that device capabilities will only indicate that a function or feature is supported if it has been successfully tested in at least two different radio networks. It is thus not possible to know whether the function or feature is supported by the wireless device in a specific network unless the function has been tested for the device in that network and in another network. The above practice may thus require that network operators coordinate deployment of functions and features in order to have them indicated as supported in the device capabilities which is needed to put the functions and features into practice. This means that a network vendor cannot typically release or activate a feature until a UE indicates support in its capabilities, i.e. after the feature has been tested with yet another network. Thus, the NW vendor needs to wait at least for another NW vendor to implement the same feature. It is therefore a problem that certain features cannot be implemented in one particular network, e.g. to address a certain market or group of users, without being also implemented in another network, and that such features would therefore not be marked as supported in the device capabilities such that they will consequently not be activated for that device in the network.
It is also a problem that even if a particular function or feature has been activated in the device capabilities, i.e. when marked as being supported by the device, a fault or problem may sometimes still be found which occurs when trying to use the function or feature. As a result, the network node may employ this function or feature in the radio communication, since it is supported according to the device capabilities, but not with successful or expected outcome.
Another problem is that considerable amounts of radio resources are used whenever a wireless device sends its capabilities to a serving network node. The quantity of capabilities that needs to be provided to the network may thus be quite extensive and is also expanding over time as more capabilities are added to support newly introduced services, functions and features. As a result, interference is also potentially generated in the network when a capability configuration is transmitted over radio. If there are errors in the reception of the full capability configuration, it may even have to be re-transmitted until it is received correctly by the network node, thus consuming additional radio resources and generating further interference in the network.